Attack On Biju
by Element-OverLord
Summary: SLIGHT AU! Eren Never Became A Titan-Shifter, Instead He Became Something Even More Dangerous Than A Titan...A BIJU! Harem And OC's.


**Attack On Biju**

**Cross/X-Over:** Attack On Titan And Naruto.

**Synopsis/Plot:** _**Eren Never Was A Titan-Shifter, Instead He Was The Reincarnation Of Something...Even More Dangerous Than A Titan...A Biju! SLIGHT AU! Harem. OC.  
**_

**DISCLAIMER:** _Attack On Titan Belongs To Hajime Isayama. Naruto Belongs To Masashi Kishimoto._

**NOTE: Some Parts Of This Chapter Were Made By yugiohfan163, So He Deserves EQUAL CREDIT!  
**

**Prologue/Chapter 0: Of Titans And Tailed Beasts**

**|Wall Maria: Shiganshina District|**

Hell...that was the only word that could describe the horror that was happening right now in Wall Maria, one of the three walls that humanity made to protect themselves from the titans. Inside these walls, humanity had lived in peace for one hundred years; many people growing up without ever having seen a Titan. This all changed when a giant 60-meter (200 ft) tall Titan mysteriously appeared and breached the outer wall of the Shiganshina district, a town at Wall Maria, allowing smaller but still deadly Titans to infiltrate the district. A second titan then smashed clean through Wall Maria, forcing mankind to abandon the land between Wall Maria and Wall Rosé, evacuating the remaining population into the inner district. But right now there were still people that were killed by the titans.

Now one young Eren Yeager watched as his mother was being picked up by that...monster. The titan held his mother with both its hands and had a sickening smile on it's faces. That was enough to drive him wild with hatred.

"Let me go! Mom's gonna be killed!" Screamed Eren who tried to get out Hannes' grip.

"She told you two to get out of here! It's too late for her!" Yelled Hannes as he ran while carrying the kids away from the monster.

Eren struggled, but saw as the titan was bringing his mom closer to its mouth. Then, something happened. Eren became filled with nothing but rage as he felt weak watching the monster about to kill his own mother!

**"AAAAAAAAAAAAAAAAAAHHHHHHHH!"** Yelled Eren as his form began to get covered in a red aura that seemed to burn as Hannes dropped Eren, and he and Mikasa were stunned to see him get back up, but his form was being covered by a darker red and saw him begin to get ears and four tails on his tailbone. Both watched as his skin and signature features were engulfed by the red aura an were stunned to see him in a different form.

His skin was blackish red as his four tails swung behind him, but stiffened as he crouched on all fours. His eyes became pure white with no pupils as his tails stood up and he charged at the beast with inhumane speed.

The titan had sensed the strange energy, and looked up. Big mistake. Eren in his new form tore straight through the titans head like it was made of paper. The action caused the creature to lose its grip on Carla as she fell and would have hit the wreckage of the house, had Eren not caught her on his back with his incredible speed.

The titan's form didn't move at all, causing Eren to feel relief even in his form. He used his tails to gently set his mother down, who was stunned at what just happened.

"E-eren?!" Asked his mother in shock before Hannes and Mikasa neared them as Eren dissapeared, making them wonder where he was before they noticed a titan near them being slayed by a red blur, showing that Eren was eliminating any titan he could find.

Hannes quickly snapped out of his shock and grabbed Carla, while being careful due to her broken legs and ribs. "We must go, there are still many titans left here..."

"But what about Eren?" Said Mikasa, not wanting to leave her beloved brother.

"Sorry," Apologized Hannes as he shaken his head and pointed to the now transformed Eren, who keep murdering any nearby titan while nearing the colossus. "But right now we can't do much to help him, we must leave. Yet I wouldn't worry about him because he keeps slaying titans like nothing."

"Even so..." Eren's mother said worriedly. "He's still a little boy! He could die if we don't do something!"

"What you think we should do?!" The survey corp snapped before calming down. "Besides, I don't think Eren would like you two to die, after all you're his beloved family. And I promise you that we'll see him again once this is over. I SWEAR!"

"...Alright..." Carla said as she and Mikasa nodded, albeit reluctantly, before Hannes took them in and went away towards the boats as the females looked worriedly at the direction where Eren went.

**|With Eren|**

Meanwhile, the now 4-tailed Eren went wild as his new found speed and strength were put to good use as he slashed the titans from their neck to down the middle. Each strike from his claws or tails were enough to finish them with ease. He looked up at the wall and bared his teeth at the Colossus Titan that caused this.

Eren let out a roar as his speed allowed him to climb the wall with ease and began to rush up the titan's arm. The Colossus saw him and tried to hit him with its other arm, but missed and saw Eren right in front of its eye before it found both its eyes slashed, blinding it.

Eren snarled as he used his claws and tails to cause as much injures as he could. He was so wrapped up in his attack that he didn't notice the arm coming close to him before he was sent flying away due to its strength. The titan soon began to disappear in a cloud of steam as Eren crashed through a building and stopped.

His crash went noticed as several members of the different corps went over to see what happened and found Eren in his normal state, unconscious.

"He looks hurt. We gotta get him to a doctor." Said one of them picking him up.

"What about the titans?" Asked one of them.

"That...red beast thing seemed to get rid of most of them. The ones that are alive seemed to be running away." Replied the leader who used his 3d gear to find a doctor with the others following.

**|Later|**

"Ugh...Where am I?" Eren asked as he regained consciousness and tried to move, but hissed in pain and looked at his body, where several bandages were wrapped around him. "What the-?!"

"So you finally woke up, kiddo?" Asked a voice and Eren looked at a familiar survey cops, who was smiling at him. "You were asleep for 2 days..."

"HANNES!" Yelled Eren in happiness before asking, "Where are mom and Mikasa!? Are they fine!?"

"Alright, alright then. Calm down Eren..." Said Hannes, "For your questions, the girls are outside the room. They wanted to come in but the doctors wouldn't let them until you recovered. And they're fine, Mikasa luckily had no wounds and Carla had her legs and ribs operated, and they're healed now."

Eren looked down as he let out a breath of relief at that. "Can I see them now?" Asked Eren.

"Considering you're awake, sure." Hannes opened the door and let in a happy Carla and Mikasa who held Eren on both sides in a hug.

"Eren, I'm so glad you're alright." Said Carla who let tears of joy and relief slide down her face.

"Eren, I'm so happy." Whispered Mikasa who held Eren a little bit tighter than their mother.

"Same here girls..." Eren said happily as he hugged his family. "Mom..."

"What is it?" Asked Carla.

"I...I'm sorry!" Apologized the boy, surprising the present. "I screamed at you earlier that day in anger...but then I had almost lost you if I hadn't..." Cried Eren before his mother hugged him, comforting the crying boy.

"There, there. I'll never leave you or Mikasa alone..."

Hannes smiled at the scene, but got their attention with a cough. "Sorry to break up this moment, but I wanted to ask Eren how he became that miniature fox."

Eren gave him a confused look before memories of what happened passed through his head. "No, not really. What happened to the titans?"

"Well, 1/10 of humanity fell from the attack, but it seems you going beast wiped out most of them before the rest took off running." Informed Hannes.

"I see..." Eren said as he realized that despite many lives being lost, his rampage had managed to save many lives and make the titans retire. "For your question, I don't remember much except rage at how the titan was about to kill mom...but then..."

"Hmm...alright then..." Hannes accepted.

"Does anyone else know about this?" Asked Eren, but it was Mikasa who answered.

"Luckily no one else knows about your transformation...but even so there were many people who saw you kill those titans and wondered who did it..." Mikasa said.

But before anyone else could say something, they saw a familiar blonde boy come in. "EREN! ARE YOU OK?!"

"A-armin!"

"Eren! I'm so glad to see you're alright!" Armin ran over and wiped some of his tears away.

"Yeah, we were lucky." Replied Eren.

"Before you go celebrating, we all need to remember that as long as there are titans, we'll have to keep fighting." Said Hannes.

All of them looked down as they knew this was true, but Eren looked up with a determined look.

"Then I'll join the Survey corps and make sure each titan is crushed!" Yelled Eren with determination.

All of them were taken back by his will, but Mikasa and Armin nodded their heads to show that they were in.

"Excuse me, but if you really want to join the Survey corps, I could train you three. I used to be part of the corp before I was married." Suggested Carla.

Each one of the kids smiled as they cheered for not only the win, but because of their chance at stopping the titans.

**|?|**

In a dark and gloomy room, several figures saw through a crystal ball the transformed Eren's rampage against the titans before one of them spoke up in a insane tone: **"FINALLY! HE APPEARED! CAN I GO FIGHT HIM NOW, PLEASE~? PRETTY PLEASE~?!"**

Then a female voice said:** "Now, Now, Ichi~! I Want To Also See This New Hunk, But We Must Wait~! Right Hachi~?"**

Then another voice answered: **"Indeed...Now We Must Make Our Remaining Brother Join Us, And Then We'll Dispose Of Those Goddamned Titans And Those Foolish Humans, Restoring The Earth To What It Was Once!"**

**"AYE, LEADER-SAMA!"**


End file.
